MANHATTAN, Kan. – The same high standards used to sterilize hospital operating rooms could soon be incorporated into meat processing plants, say meat safety researchers at Kansas State University.

They’re studying "clean-room" technology that they say is the best step to eliminating the foodborne pathogen, listeria monocytogenes, in such ready-to-eat products as sliced deli meats, hams, hot dogs, pepperoni and salami.

According to K-State Research and Extension microbiologist Randy Phebus, the study addresses a tangible consumer concern. A recent USDA study indicated nearly 5 percent of the country’s ready-to-eat meats are infected with listeria monocytogenes, a foodborne bacterium that can be fatal due to blood poisoning, meningitis or meningo-encephalitis (a disease that affects the tissues of the spine and brain). In pregnant women, listeria can cause the fetus to be aborted or stillborn.

But K-State researchers think they can ease consumer fears. The university has developed a "clean room" based on limiting employee access to meat processing areas; controlling a room’s air flow; and utilizing cleaning and sanitation methods.

"What truly makes it a clean room is the controlled access. Access in and out is very strict so that people are not bringing in organisms or bacteria on their clothes or by other means," Phebus said.

The room is pressurized to prevent organisms from being "sucked in," he said. Nearly 50 times an hour, the air in the room is re-circulated with "virtually sterile air." Filters are used to reduce bacteria to nearly-undetectable levels.

Phebus said the room is regularly cleaned and sanitized to kill bacteria that might have found its way past these other defenses.

The environment K-State has developed has received high ratings for air quality.

"[It’s called] ‘Class 10,000,’ which means that there is only 10,000 [air] particles per cubic foot," Phebus said. "The air we regularly breath contains anywhere from 1 million to 10 million particles per cubic foot. That is an extreme reduction [of air particles]."

Ready-to-eat meats have a shelf life of 3-6 months. Steam pasteurization will help eliminate listeria that may be present during processing and, thus, decrease the potential that the bacteria can multiply while sitting on the grocery store shelf.

"What the consumer is interested in is that the finished product will be safe. They don’t really care about the manufacturing facilities," Phebus said. "They want the product they bring into their house to be safe and wholesome."

Marsden said steam pasteurized meats represent "a big culture change for the [meat] industry."

"When this process got started it wasn’t a matter of money. Companies wanted to jump right in," Marsden said. "[But] they started using hot water instead of steam, and found out that it was cooking the product. They were changing the look [of the meat] and it didn’t have the same taste."

Steam pasteurization, Marsden said, does not change the quality or taste of the product, which can be purchased at the peak of freshness.

"We really think we hit a home run with this system," he said.

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus in Manhattan.